Conventionally, to close off the opening of a vehicle, whether concerning an automobile, a utility vehicle, a lorry, a bus or a railroad car, a window is added, maintained by a connecting surround. The latter has an internal portion and an external wall, which simultaneously pinches the edges of the glass and of the aperture formed in the bodywork, with a seal lining.
The most widespread technique for the opening and the closing of a door window is that of rendering the latter mobile vertically in its own plane, by having it penetrate or exit the housing or the lining of the door. Horizontally sliding panels are also known, along rails formed in a surround.
This technique is commonly used today and solutions for automating it are known. Providing automobiles with electric windows is today very widespread.
This technique however has many disadvantages concerning, in particular, problems with sealing.
Another technique has been proposed by the holder of this patent application. This technique is in particular described in patent documents EP-0 778 168 and EP-0 857 844. The device for closing off (called “flush opening” in what follows) presented in these documents includes a fixed structure and a portion, or slide panel, that is mobile in relation to this fixed unit. The mobile portion is connected to the fixed unit by functional elements that provide for the required mobility and which are added on the face of the fixed portion turned towards the interior of the vehicle.
Such a flush opening can be mounted fully independently of the vehicle, and added, from the exterior, in the housing defined for this purpose on the bodywork of the vehicle. It can also be fastened, in particular by gluing to the lower portion of a door, according to the technique described in patent document EP-1 022 172. As such, most of the sealing problems identified hereinabove are resolved.
From an aesthetical standpoint, the flush opening has, viewed from the exterior, a smooth, flush aspect, due to the fact that no surround is required on the outline of the aperture formed in the fixed unit.
In order to provide a sliding of the mobile portion, constituted in general by a transparent panel, a guide device is provided for example comprising a first and second guide rails fixedly mounted on the fixed unit (or fixed structure) of the opening, on either side of the aperture closed by the mobile panel. The latter is mounted on the rails, in order to slide for example according to a longitudinal direction, in a plane of sliding between one (or several) opening positions and an intermediary clearing position wherein it is across from the opening and cleared from the latter.
Note that it has been considered to displace the mobile portion between the closing off position and the intermediary clearing position according to two techniques primarily:                a first technique for which the displacement of the mobile portion is a combination of a movement in a direction parallel to the plane of the fixed portion and of a movement in a direction perpendicular to this plane, in the form of a general wandering movement, according to which the distal edge of the mobile portion is located, at the end of travel, in the plane of the opening (the mobile portion then being “across”, between the plane of closing off and the plane of sliding). It is then sufficient to bring the proximal edge, for example manually, in order to provide for the closing off; and        a second technique for which the mobile portion remains constantly in a plane that is substantially parallel to the plane of the fixed portion during its displacement.        
The invention relates more particularly to this second technique of closing off, to its alternatives and its perfections. More precisely, the inventors are aiming via this document to propose at least one new technique for guiding and for locking such “flush openings”. However, the invention can in a wider manner apply to all devices for closing off of which the opening and/or closing kinematics includes a displacement (in y) between an opening position and an intermediary clearing position, in a plane parallel to the plane of the fixed unit, and a displacement (in x) in this parallel plane.
It is known, for example from FR-2 833 209 of the same Applicant as this application, a guiding technique for a mobile panel of “flush opening” in rails implementing guiding pegs circulating in non-straight grooves formed in rails.
A disadvantage of this technique is that the implementation of the rails is complex.
Another disadvantage of this technique is that the rails are sometimes of substantial thickness in order to allow for the guiding of the pegs satisfactorily, which can interfere with the transparency of the opening.
Moreover, with regards to the locking operation of the flush openings, several solutions have been proposed to lock the sliding panel(s) in the closing off position of the aperture provided in the opening, and where applicable in selected positions of opening.
Among the latter, a technique is known shown in EP-1 659 247, according to which at least one bolt cooperating with a strike plate is provided formed in one of the rails perpendicularly to the axis of sliding of this rail, the passing from a locked position to an unlocked position resulting from the displacement of the sliding panel from a first plane towards a second plane substantially in the direction perpendicular to the axis of the rail.
A disadvantage of these techniques of the prior art is that it requires to proceed with an effort, for example a tightening effort, in order to immobilise the panel in a locked position, which is not practical and is sometimes not very effective. This moreover renders these techniques complex, since it is necessary to provide additional means of blocking in order to effectively lock the sliding panel.
Another disadvantage of these techniques of prior art is that they do not permit, or do not offer a simple or effective solution, for stopping the sliding of the panel in any total or intermediary opening position.